Tube-forming apparatus.



No. 734,299. PATENTED JULY 21, 1903.

' W. CAIRNS.

TUBE FORMING APPARATUS.

N APPLICATION FILED D50. 12, 1902.

N0 MODEL. 2 SHEETS-SHEET 1.

TVZ'tzzesss v 2167i 601 No. 734,299. 1 V PATENTED JULY 21, 1903. W.CAIRNS. TUBE FORMING APPARATUS.

- APPLIOATION FILED DBO. 12, 1902.

N0 MODEL. I Z'HHEETS-SHEET 2.

UNITED STATES l E atented-duly 21, 19021 PATENT OFFICE.

' WVILLIAM CAIRNS, OF ELYRI A, OHIO, AS SIGNOR TO THE ELYRIA IRON ANDSTEEL COMPANY, OF ELYRIA, OHIO, A CORPORATION OF OHIO.

TUBE-FORMING APPARATUS.

SPECIFICATION forming part of Letters Patent N 0. 734,299, dated July21, 1903. Application filed December 12,1902. Serial No- 134,967. (Nomodel.)

To all whom it may concern.-

Be it known that I, WILLIAM CAIRNS, a citi- Zen of the United States,residing at Elyria,

in the county of Lorain and State of Ohio,

have invented a certain new and useful Improvement in Tube-FormingApparatus, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings.

By the method generally employed for bending metal strips into tubularform the strip or skelp is first bent longitudinally midway between itsedges into U shape, the sides of the U being after this initial bendingsubstantially straight and nearly parallel. This bent trough-likestructure is then forced through a suitable former by which thesestraight sides are gradually bent to bring their edges together, and thetube is finished as well as may be between finishing-rolls. This methodof making tubes is objectionable,

because it is practically impossible to bend By the method which themechanism here- I inafter described is adapted to carry out the skelp isfirst bent longitudinally along both its edges into the circular arcform whichthey ought to have in the finished tube; and. then theintermediate part of the slielpisbent gradually and progressively towardthe 3 longitudinal center thereof until the initiallycurved edges are incontact, and thereby; there is formed a tube which is a perfect,

1 change in the radius *of curvature.

circle in cross-section.

The invention relates to mechanism for' bending the skelp int-o tubularform by the method last above referred to; and the inveution of themechanism embodying my inven-,

tion. Fig. 2 is a plan view thereof. Fig. 3 is a front view of the rollsfor initially bending the skelp. Fig. 4 is a plan View of the formerinto which the initially-bent skelp passes after leaving theforming-rolls. Fig. 5

. .is a side View, partlyin longitudinal vertical section, of saidformer. Figs. 6, 7, S, 9 and 10 are respectively transverse verticalsectional views of said former in the planes of lines 6 6 7 7 8 8 0 9 1010, respectively.

Referring to the parts by letters, A B' represent two forming-rollsmounted in suitable housings O C. On the periphery of the roll I A is anannular tongue at, which isfitted to the annular groove 12 in theperiphery of the roll B, the space between the tongue and groove beingof the shape in whichit is desired to initially bend the skelp. The faceof the tongue at is flat; but the sides thereof are curved into circulararcs of something less than ninety degrees of the same radius as thefinished tube is to be, and the groove 1) is similarly formed.

D and E represent two finishing rolls mounted in suitable housings Casuitable distance from the rolls A B. Each of these rolls D and E has asubstantially semic'ylindrical groove in its periphery, one of whichgrooves is indicated by d inFig. 2. Between these pairs of rolls is aformer, haviugbetween the fixed bottom plate G and the removablecoverplate F, which rests upon the bottom plate, a channel, which at theeutrance end is shaped to fit the bent skelp as it emerges' from theforming-rolls A and B.- that is to say, this channel is flat in itsmiddle part; but at its'sides it is curved upward in circular arcs. Inassuming the cylindrical form the fiat middle part of the channelgradually grows narrower, while the curved sides thereof graduallyincrease in length without change of the form is gradual and such thatthe curve initially given to the edges of the skelp is graduallyextended'inward toward the longitudinal center, which is the last partof the skelp to be given this circular curve.

A mandrel M, which is anchored to the cover plate at a suitable point,extends through this channel and out of thedischarge end thereof and' toa point between the finishing-rolls D E. As the skelp is bent bytheformer the edges are carried over and around this mandrel. On the innerside of the coverplate there is a centrally-placed longitudinal tongue1, of gradually decreasing width,

The

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' unequal bending of the skelp on oppositesidesofthelongitudinalcenterthereof. This tongue also holds the mandreldown, so that it shall always be the proper distance from the bottom ofthe channel.

The cover-plate F is made of two parts, of which the partfcovers thereceiving end of the channel and the parlf covers the delivery end. Atthe receiving end of the former both the bottom plate and cover-plateare curved to fit the curvature of the rollsA B, between which they passas far as practicablethat is to say, these curved edges touch or almosttouch the faces of the rolls just behind the plane in which these rollsare nearest together. The partf of the cover-plate projects at its otherend under a lip f project ing from the part f. A set-screw H passesthrough a lugf on top of the partfand engages with the end of said lip fBy turning the setscrew the position of the part f relative to the rollsA B may be regulated. The part f of the cover-plate is held down uponthe base-plate by the following means, to wit: Two lugs g project upwardfrom the base-plate on opposite sides of the coverplate, and theirprojecting upper ends are undercut. Two lugs extend laterally from thecover-plate and are beveled to fit beneath the undercut portion of saidlugs. Near the opposite end of the cover-plate there are two side lugs 9extending up from the baseplate, which are also undercut. A wedgeshapedkey N, resting upon the cover-plate, bears at one side against ashoulderf thereon, while its other edge is beveled and engages beneaththe undercut portions of the lugs 9 K represents a guide for deliveringthe skelp properly to the rolls A B. As shown, it is a trough-like platehaving a cover 7.), whose upward movement is prevented by theoverhanging lugs 7t.

In using the described apparatus the skelp J is first cut into V shapeat its front end, so that it may enter between the rolls A B. The skelpis then pushed along in the guide K by hand or by mechanism, as deemedadvisable, until the pointed front end thereof passes between the rollsA B. Thereafter these rolls not only initially bend the sides of theskelp, but also force it along through the former G, by which it iscurved, as stated. When it emerges from the former, it is almost a cylinder, and it embraces the mandrel, the front swelled end on of which liesbetween the two finishing-rolls D E. These rolls complete the tube,bending it closely over the swelled end of said mandrel.

Having described my invention, I claim 1. In an apparatus for formingtubes, the combination of two forming-rolls having respectively a tongueand groove whose faces are fiat and whose sides are curved in circulararcs, with a former into which the bent skelp is delivered from saidrolls, which former contains a channel which fits the bent skelp as itis delivered from said roll, and which gradually assumes a circular formin cross-section, a mandrel in said channel anchored to the top wallthereof and extending out of the delivery end, and two grooved finishing-rolls between which the end of said mandrel projects.

2. In an apparatus for forming metal tubes, a former consisting of abase-plate and a removable cover-plate between which is a channel havinga flat center of gradually-decreasing width from the receiving to thedelivery end thereof and having are shaped sides which increase inlength without changing the radius of curvature.

3. In an apparatus for forming tubes, a former consisting of abase-plate, and a coverplate, between which is a forming-channel, saidcover-plate being formed in two parts of which the part covering thedelivery end of the channel has a lip which overhangs the part coveringthe receiving end thereof, a set-screw carried by one of saidcover-plate sections and engaging with the other, and means for securingtogether the base-plate and that part of the cover-plate which is at thedelivery end of the former.

4. In an apparatus for forming metal tubes, a former curved at its frontend to fit the curvature of a pair of rolls, and consistingof a fixedbase-plate, and a cover-plate which rests upon the base-plate, and isformed of two parts of which the part, whose front end is curved, liesbeneath a lip on the other part, a set-screw carried by the front partand engaging with the other part, there being between the base-plate andthe two-part coverplate a. forming-channel, and means for securingtogether the base-plate and that end of the cover-plate which is at thedelivery end of said former.

In testimony whereof I hereunto afiiix my signature in the presence oftwo witnesses.

WILLIAM CAIRNS.

Witnesses:

E. B. GILOHRIST, E. L. THURSTON.

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